Data Manipulation

KeLP is a general-purpose machine learning platform and does not cover any feature extraction aspect. However it provides some simple data preprocessing features to manipulate the input data. Specific operations on data can be defined by implementing the Manipulator interface. Instances of such class can be then passed to the method manipulate of the class Dataset in order to perform the manipulation operations on the whole dataset.

NormalizationManipolator: it scales vector representations in order to be a unit vector in its explicit feature space. This can be useful when the orientation of the feature vectors is meaningful, while their magnitude is not relevant;

StandardizationManipulator: it standardizes the feature values of a vectorial representation. Let be the value of the i-th feature whose mean and standard deviation are and respectively. Then, the standardized value is . This operation is useful in order to map all the features to a similar range.